Field of the Invention
The present invention relates to an exhaust heat recovery apparatus that recovers exhaust heat discarded after engine combustion of a vehicle and uses the collected exhaust heat, and more particularly, to a rotary-type exhaust heat recovery apparatus capable of simultaneously serving as a bypass valve and a heat exchanger by rotatably providing a semi-cylindrical heat exchanger in which one surface with a rotation axis as its reference is closed and the other surface is opened within an exhaust gas pipe.
Description of Related Art
In general, a vehicle performs a warm-up step and a heating step in an early stage of starting, a thermoelectric generating step during the running of the vehicle, and a bypass step when the vehicle runs on an inclined road or runs at an excessive speed, depending on a running state of the vehicle.
An exhaust heat recovery apparatus of the vehicle is an apparatus that recovers exhaust heat discarded after engine combustion to use the recovered exhaust heat for a warm-up of the engine and a warm-up of a transmission, or transmits recovered heat energy to an air conditioning device to use the transmitted heat energy to heat the inside of the vehicle.
When the exhaust heat recovery apparatus of the vehicle is used, a coolant can be heated using a high-temperature exhaust gas in an early stage of starting. Thus, a pre-heating time of the engine is reduced, so that it is possible to improve fuel efficiency and to reduce the exhaust gas.
The largest amount of contaminants is discharged from the vehicle at the time of idling before the engine is warmed up, and it is possible to reduce contaminants discharged from the vehicle by using the exhaust heat recovery apparatus to reduce the warm-up time.
It is also possible to reduce friction within the engine and friction within the transmission by rapidly increasing temperatures of an engine coolant and transmission oil by using the coolant heated through the exhaust heat recovery apparatus. Furthermore, it is possible to rapidly heat the inside of the vehicle in the winter time.
As illustrated in FIGS. 1A and 1B, an exhaust heat recovery apparatus of a vehicle according to the related art has a structure in which a bypass valve 5 that can be rotated by a valve actuator 6 is provided at a bypass path 4 and a heat exchanger 3 including a coolant path 1 and an exhaust gas path 2 is attached to a side of the bypass path 4.
As illustrated in FIG. 1B, when the bypass path 4 is closed by the bypass valve 5, an exhaust gas is induced toward the heat exchanger 3, and a temperature of an operating fluid is increased due to heat exchange between a high-temperature exhaust gas flowing in the exhaust gas path 2 of the heat exchanger and a low-temperature coolant flowing in the coolant path 1, so that an engine and a transmission are warmed up.
However, in the exhaust heat recovery apparatus according to the related art, since the number of components such as the heat exchanger, the bypass path, the bypass valve and the valve actuator is excessively large, a structure thereof may be complicated, and manufacturing cost and weight thereof may be excessively increased.
In the exhaust heat recovery apparatus according to the related art, when the bypass path is opened, that is, the bypass is performed, since it is difficult to prevent the exhaust gas from being introduced into the heat exchanger, heat-insulating performance of the coolant may be degraded. Furthermore, when the exhaust gas is bypassed, if a separate valve operating link structure is added to prevent the exhaust gas from being introduced into the heat exchanger, an assembly process may be complicated, and manufacturing cost may be increased.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.